1. Field of the Invention
The present invention relates to a method of setting ID number within a radio communication system used for data transmission within a station yard or the like.
2. Description of the Prior Art
When two or more radio communication systems each comprising a base station and plural hand held terminals, which is used within a station yard or the like, exist closely to each other, they may interfere with each other. In such a case, an ID number identified only within the same system and common to all base stations and hand held terminals within the same system (hereinafter referred to as "system ID number") is set. When a system ID number other than the proper system ID number is received, such radio wave is determined as coming from another system, whereby an interference is prevented. Conventionally, the aforementioned system ID number has a fixed value set beforehand on both base station and hand held terminal by hardware such as bit switch, small capacity ROM or the like.
However, such prior art construction requires special hardware for setting the system ID number, which inevitably prevents the miniaturization of a hand held terminal particularly for portable use. Since the system ID number is fixed by hardware, when the hand held terminal is used on another system (having a different system ID number), the system ID number setting hardware must be changed or replaced, which is uneconomical and ineffective.